he English language abstract of JP 01041721 A discloses a baking oven having a vapor duct in which a catalyst is disposed in such a manner that vapors which are generated in the baking oven and removed through the vapor duct must pass through the catalyst, and that a humidity sensor connected in signal communication with a controller of the baking oven is disposed downstream of the catalyst. The humidity sensor is used to determine the soil level of the oven chamber of the baking oven. The objective of this is to keep to the absolute minimum the time during which the oven chamber is heated to a temperature of 500° C. for purposes of pyrolytic cleaning.
German Patent Application DE 43 41410A1 describes a baking oven that uses a humidity sensor in the form of a semiconductor gas sensor. However, no specific information is provided on the exact arrangement of the sensor in the vapor duct.